Hello EPJ and welcome to the Overwatch forums. While it was not your intention to leave, crashing or disconnecting does negatively impact competitive games and causes matches to either cancel or leave a team a man down for the remainder of the match. Because of this penalties stand even if you crash and disconnect. This is done because it prevents deliberate leavers from having any means to bypass penalties and encourages those who encounter crashes or disconnections to stop playing Competitive Play and troubleshoot their issues. You can learn more about Blizzard’s policy about this here:
If you are getting this error dialog appearing…
…this is often due to outdated drivers or a conflicting program. Please follow these steps first if you have not already.
If nothing helps, please go ahead and start a web ticket and share those crash errors in the ticket. Please also remember to add your system files so that Blizzard can learn about your computer quickly.
Obtaining System Files: https://us.battle.net/support/en/article/12988
Starting a web ticket: Get Help - Blizzard Support
When servers crash the usual behavior is that both teams will be returned to the lobby and the message “Server closed due to an unexpected error” appears in the text chat and the match will immediately restart (often on a new map) with those players. The results of the crashed match is void.